In order to perform microprocessing such as etching process or film forming process on a processing target substrate such as a semiconductor substrate, a solar cell substrate or a liquid crystal substrate, there is known a substrate processing apparatus configured to mount the processing target substrate on a mounting table, supply a processing gas onto the processing target substrate and perform a required process on the processing target substrate by plasma excited from the processing gas.
In such a substrate processing apparatus, a temperature in a surface of the mounting table is controlled in order to control processing uniformity in a surface of the substrate. For example, widely employed is a method of forming, within the mounting table, a coolant path or passage through which a coolant is flown. In this method, a temperature-controlled coolant is supplied into and circulated through the coolant path from a chiller device.
Recently, as a processing dimension in a plasma process is miniaturized and the plasma process is diversified, techniques to conduct a temperature distribution control of the mounting table are also diversified. For example, Patent Document 1 describes a configuration where an upper heat medium path and a lower heat medium path are formed in the entire surface of a mounting table. A cooling medium and a heating medium are selectively supplied into corresponding one of these heat medium paths as a heat medium. In this configuration, a temperature of the mounting table can be controlled to be a high temperature or a low temperature in both ways.
Further, described in Patent Document 2 is a configuration where a coolant path is divided in two parts corresponding to a central portion and a peripheral portion of a mounting table, respectively. In this configuration, by switching lines through which a coolant from a chiller unit is circulated, the coolant is controlled to be circulated in the central portion or in the peripheral portion of the mounting table, thus controlling temperatures of the central portion and the peripheral portion of the mounting table.